Automated Endoscope Reprocessors Research Articles

Potential for residual contamination by Streptococcus equi subspp equi of endoscopes and twitches used in diagnosis of carriers of strangles.

Endoscopic examinations are essential for diagnosis and treatment of strangles (Sequi infection) in horses. However, even after disinfection, endoscopes may retain viable bacteria or bacterial DNA. Twitches are commonly used during endoscopic examinations and can thus also potentially transmit the organism to other horses. To evaluate the efficacy of different disinfectant methods to eliminate Sequi from experimentally contaminated endoscopes and twitches and the effectiveness of field disinfection of endoscopes used in sampling carriers of Sequi. Experimental contamination and observational field study. One endoscope and 30 twitches were contaminated with standardised Sequi broth solutions. The endoscope was disinfected following three protocols using various disinfectants for manual disinfection. A fourth protocol used an automated endoscope reprocessor (AER). The twitches (n =30) were disinfected following eight different disinfecting protocols. Three endoscopes used in sampling for silent carriers were disinfected following a field-based protocol. After each protocol the endoscopes and twitches were sampled for Sequi by culture and qPCR. Following experimental contamination all endoscope disinfection protocols, apart from 1/6 of the ethanol protocol were Sequi culture negative. However, no endoscope disinfection protocol completely eliminated retention of Sequi DNA. Field disinfection of endoscopes after sampling carriers yielded no culture positives and all but one (13/14) were qPCR negative. All twitches disinfected following experimental contamination were culture negative but sodium hypochlorite was the only disinfectant that completely eliminated detection of Sequi DNA. Experimental contamination may not reflect the numbers of Sequi transferred to endoscopes or twitches during use on silent carriers and purulent secretions from infected horses may influence survival of Sequi. While most disinfection methods appear to ensure removal of cultivable Sequi, residual DNA can remain on both endoscopes and twitches.

Microbiological surveillance of endoscopes and implications for current reprocessing procedures adopted by an Italian teaching hospital.

Hospital acquired infections have been associated with the contamination of flexible endoscopes caused by a failure of the reprocessing procedure. Microbiological surveillance of endoscope reprocessing is valuable for assessing contamination by pathogens. The aim of this study is to evaluate microbiological contamination of endoscopes after reprocessing, and the involvement of reprocessing procedures adopted in endoscopy units of an Italian teaching-hospital. The study was carried out, on several dates in 2014, in 11 endoscopic operation units equipped with 100 endoscopes (18 bronchoscopes, 41 gastroduodenoscopes, 29 colonoscopes, 12 laryngoscopes) and 9 Automated Endoscope Reprocessors. Presence/absence of common pathogens and indicator micro-organisms (including multi-drug resistant bacteria) and Total Microbiological Count (TMC) were obtained from the biopsy channels of endoscopes after reprocessing, from final rinse water of automated endoscope reprocessors and from tap water applying standard microbiological culture methods. Following the European Guidelines for quality assurance in reprocessing, the post-reprocessing criteria were "absence of indicator micro-organisms and absence of TMC in samples obtained from endoscopes' channels". A total of 180 samples were collected (143 endoscopes, 25 Automated Endoscope Reprocessors and 12 water supply). Compliance to the European Guidelines was achieved for 112 out of the 180 (62.2%) samples analyzed. Presence of indicator micro-organisms (mainly Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa and other Gram-negative non-fermenting bacteria) was found in 51 out of 143 endoscopes (35.7%). Multi-drug resistant bacteria were also found. Presence of pathogen micro-organisms was statistically associated with the increase of TMC level, but not with time after reprocessing. The study provides information about the microbiological quality of endoscope reprocessing procedures adopted by different endoscopic operation units. The high prevalence of contaminated endoscopes provides evidence of the need to improve the quality of reprocessing.

1223. Endoscopic Retrograde Cholangiopancreatography (ERCP)-Associated Carbapenem-resistant Enterobacteriaceae (CRE) Before and After Implementation of Ethylene Oxide (ETO) Sterilization of Duodenoscopes

BackgroundReusable duodenoscopes utilized for Endoscopic Retrograde Cholangiopancreatography (ERCP) procedures are challenging to clean thoroughly. Outbreaks of carbapenem-resistant Enterobacteriaceae (CRE) have been associated with the use of duodenoscopes even when no clear breaches in manufacturer-recommended manual cleaning and high-level disinfection have been found. We evaluate the impact of implementation of ethylene oxide (ETO) sterilization on rates of ERCP-associated CRE.MethodsThe charts of all patients who developed CRE colonization or infection between 2012 and 2018 in a large tertiary care teaching hospital were reviewed to determine whether the patient had an ERCP in the 90 days prior to the CRE culture date. Rates of CRE acquisition per 100 ERCPs performed were calculated and compared pre (ERCP performed January 2012 through February 2015) and post-implementation (ERCP performed March 2015 thru December 2018) of routine ETO sterilization of duodenoscope following high-level disinfection (HLD) with an automatic endoscope reprocessor (AER) rather than HLD alone.ResultsBetween 2012 and 2018, 44 patients had first clinical culture with CRE within 90 days of ERCP (36% blood, 34% wound/surgical, 25% urinary and 7% respiratory sources). ETO sterilization of duodenoscopes following manufacturer recommended HLD was implemented March 2015. Rates of first CRE clinical culture within 90 days of ERCP decreased from 0.80 with HLD alone to 0.25 per 100 ERCP procedures with HLD plus ETO (unadjusted IRR 0.31 ETO vs. HLD alone, 95% CI 0.16–0.57, p-value < 0.001). This decrease occurred despite implementation of updated CLSI carbapenem breakpoints in July 2016. Figure 1 shows post ERCP CRE clinical culture trends over timeConclusionImplementation of ETO sterilization for duodenoscopes following HLD reduced our rates of post ERCP CRE in clinical cultures within 90 days of the procedure. Disclosures All authors: No reported disclosures.

Duodenoscope-Associated Infections: Update on an Emerging Problem.

The duodenoscope is among the most complex medical instruments that undergo disinfection between patients. Transmission of infection by contaminated scopes has remained a challenge since its inception. Notable risk factors for pathogen transmission include non-adherence to disinfection guidelines, encouragement of biofilm deposition due to complex design and surface defects and contaminated automated endoscope reprocessors. The most common infections following endoscopy are endogenous infections involving the patient's own gut flora. Exogenous infections, on the other hand, are associated with contaminated scopes and can theoretically be prevented by effective reprocessing. Pseudomonas aeruginosa is currently the most common organism isolated from contaminated endoscopes. Of note, reports of multidrug-resistant duodenoscopy-associated outbreaks have surfaced recently, many of which occurred despite adequate reprocessing. The FDA and CDC currently recommend comprehensive cleaning followed with at least high-level disinfection for reprocessing of flexible GI endoscopes. Reports of duodenoscope-related outbreaks despite compliance with established guidelines have prompted professional and government bodies to revisit existing guidelines and offer supplementary recommendations for duodenoscope processing. For the purposes of this review, we identified reports of duodenoscope-associated infections from 2000 till date. For each outbreak, we noted the organisms isolated, the number of cases reported, any possible explanations of contamination, and the measures undertaken to end each outbreak. We have also attempted to present an overview of recent developments in this rapidly evolving field.

Mycobacterium avium pseudo-outbreak associated with an outpatient bronchoscopy clinic: Lessons for reprocessing.

We identified a pseudo-outbreak of Mycobacterium avium in an outpatient bronchoscopy clinic following an increase in clinic procedure volume. We terminated the pseudo-outbreak by increasing the frequency of automated endoscope reprocessors (AER) filter changes from quarterly to monthly. Filter changing schedules should depend on use rather than fixed time intervals.

A state-wide survey of disinfection techniques for nasendoscopies in Queensland ENT out-patient departments

Background: Flexible nasendoscopy is an important part of the diagnostic process in Otorhinolaryngology. Flexible nasendoscopies come in close contact with mucous membranes of the upper aerodigestive tract. Therefore, appropriate and effective disinfection is vital to prevent iatrogenic infection and cross contamination. The lack of official national reprocessing guidelines has led to varying and inconsistent practice amongst ENT centres in Australia. Methods: A questionnaire was sent to 14 Queensland ENT out-patient departments to establish current practice. Results: In total, 50% (N=7) of hospitals used manual disinfection and 50% (N=7) used automated endoscope reprocessors (AEMs). Manual disinfection with Tristel was used in most (N=6) departments and Cidex was used in one hospital. The same disinfection technique was used after hours and in high risk patients (HIV, hepatitis B, hepatitis C, pulmonary tuberculosis) in all hospitals. The efficacy and time to reprocess were the main factors that influenced the disinfection techniques used. The majority (64.3%) of centres cleaned nasendoscopies in the ENT out-patient department and remaining hospitals (35.7%) did so in the Central Sterile Services Department (CSSD). A permanent record of nasendoscopy maintenance, reprocessing and patient tracking system was used in all departments. Conclusions: The disinfection techniques and disinfectant agents vary considerably across ENT out-patient departments in Queensland. Hence, a state wide disinfection guideline would be beneficial to ensure that reprocessing of nasendoscopies is standardised regardless of the technique used across the state.

Simethicone is retained in endoscopes despite reprocessing: impact of its use on working channel fluid retention and adenosine triphosphate bioluminescence values (with video)

Studies from our group and others demonstrate residual fluid in 42% to 95% of endoscope working channels despite high-level disinfection and drying. Additionally, persistent simethicone has been reported in endoscope channels despite reprocessing. Endoscopy was performed by using water or varied simethicone concentrations (0.5%, 1%, 3%) for flushing. After high-level disinfection/drying, we inspected endoscope working channels for retained fluid by using the SteriCam borescope. Working channel rinsates were evaluated for adenosine triphosphate (ATP) bioluminescence. Fourier transform infrared spectroscopy was performed on fluid droplets gathered from a colonoscope in which low-concentration simethicone was used. Use of medium/high concentrations of simethicone resulted in a higher mean number of fluid droplets (13.5/17.3 droplets, respectively) and ATP bioluminescence values (20.6/23 relative light units [RLUs], respectively) compared with that of procedures using only water (6.3 droplets/10.9 RLUs; P< .001). Two automated endoscope reprocessing cycles resulted in return of a fluid droplet and ATP bioluminescence values to ranges similar to that of procedures that used only water (P= .56). Low-concentration simethicone did not increase the mean residual fluid or ATP bioluminescence values compared with procedures that used only water (5.8 droplets/15.6 RLUs). Fourier transform infrared analysis revealed simethicone in the endoscope working channel after use of low-concentration simethicone. Use of medium/high concentrations of simethicone is associated with retention of increased fluid droplets and higher ATP bioluminescence values in endoscope working channels, compared with endoscopes in which water or low concentration simethicone was used. However, simethicone is detectable in endoscopes despite reprocessing, even when it is utilized in low concentrations. Our data suggest that when simethicone is used, it should be used in the lowest concentration possible. Facilities may consider 2 automated endoscope reprocessor cycles for reprocessing of endoscopes when simethicone has been used.

Optimizing Endoscope Reprocessing Resources Via Process Flow Queuing Analysis.

The Massachusetts General Hospital (MGH) is merging its older endoscope processing facilities into a single new facility that will enable high-level disinfection of endoscopes for both the ORs and Endoscopy Suite, leveraging economies of scale for improved patient care and optimal use of resources. Finalized resource planning was necessary for the merging of facilities to optimize staffing and make final equipment selections to support the nearly 33,000 annual endoscopy cases. To accomplish this, we employed operations management methodologies, analyzing the physical process flow of scopes throughout the existing Endoscopy Suite and ORs and mapping the future state capacity of the new reprocessing facility. Further, our analysis required the incorporation of historical case and reprocessing volumes in a multi-server queuing model to identify any potential wait times as a result of the new reprocessing cycle. We also performed sensitivity analysis to understand the impact of future case volume growth. We found that our future-state reprocessing facility, given planned capital expenditures for automated endoscope reprocessors (AERs) and pre-processing sinks, could easily accommodate current scope volume well within the necessary pre-cleaning-to-sink reprocessing time limit recommended by manufacturers. Further, in its current planned state, our model suggested that the future endoscope reprocessing suite at MGH could support an increase in volume of at least 90% over the next several years. Our work suggests that with simple mathematical analysis of historic case data, significant changes to a complex perioperative environment can be made with ease while keeping patient safety as the top priority.

High-quality endoscope reprocessing decreases endoscope contamination

ObjectivesSeveral outbreaks of severe infections due to contamination of gastrointestinal (GI) endoscopes, mainly duodenoscopes, have been described. The rate of microbial endoscope contamination varies dramatically in literature. The aim of this multicentre prospective study was to evaluate the hygiene quality of endoscopes and automated endoscope reprocessors (AERs) in Tyrol/Austria. MethodsIn 2015 and 2016, a total of 463 GI endoscopes and 105 AERs from 29 endoscopy centres were analysed by a routine (R) and a combined routine and advanced (CRA) sampling procedure and investigated for microbial contamination by culture-based and molecular-based analyses. ResultsThe contamination rate of GI endoscopes was 1.3%–4.6% according to the national guideline, suggesting that 1.3–4.6 patients out of 100 could have had contacts with hygiene-relevant microorganisms through an endoscopic intervention. Comparison of R and CRA sampling showed 1.8% of R versus 4.6% of CRA failing the acceptance criteria in phase I and 1.3% of R versus 3.0% of CRA samples failing in phase II. The most commonly identified indicator organism was Pseudomonas spp., mainly Pseudomonas oleovorans. None of the tested viruses were detected in 40 samples. While AERs in phase I failed (n = 9, 17.6%) mainly due to technical faults, phase II revealed lapses (n = 6, 11.5%) only on account of microbial contamination of the last rinsing water, mainly with Pseudomonas spp. ConclusionsIn the present study the contamination rate of endoscopes was low compared with results from other European countries, possibly due to the high quality of endoscope reprocessing, drying and storage.

Impact of cleaning monitoring combined with channel purge storage on elimination of Escherichia coli and environmental bacteria from duodenoscopes

We aimed to determine whether monitoring of duodenoscope cleaning by rapid adenosine triphosphate (ATP) combined with channel-purge storage could eliminate high-concern microorganisms. In a simulated-use study, suction channels, as well as lever recesses, from 2 duodenoscopes models and the unsealed elevator guidewire (EGW) channel from 1 of these 2 duodenoscopes (the other model has a sealed EGW) were perfused with ATS2015 containing approximately 8 Log10 colony-forming units (CFU)/mL of both Enterococcus faecalis and Escherichia coli. Pump-assisted cleaning was monitored by rapid ATP testing. Duodenoscopes exceeding 200 relative light units (RLUs) were recleaned. Clean duodenoscopes were processed through an automated endoscope reprocessor and then stored in a channel-purge storage cabinet for 1 to 3 days. Cultures of EGW channel and instrument channel combined with the lever recess (IC-LR) were taken after storage. The impacts of extended cleaning and alcohol flush were evaluated. E coli was reliably eliminated in IC-LR and EGW channels of 119 duodenoscope tests (59 with sealed EGW and 60 with nonsealed EGW). However, actionable levels of E faecalis and environmental bacteria persisted. Neither alcohol flush nor extended cleaning resulted in a reduction of actionable levels for these organisms. Identification of isolates indicated that residual organisms in duodenoscope channels were hardy Gram-positive bacteria (often spore formers) that likely originated from environmental sources. These data indicate that high-concern Gram-negative bacteria but not E faecalis or environmental bacteria can be reliably eliminated by use of the manufacturer's instructions for reprocessing with ATP monitoring of cleaning and channel-purge storage conditions.

Bacterial presence on flexible endoscopes vs time since disinfection.

AIMTo correlate the length of endoscope hang time and number of bacteria cultured prior to use.METHODSProspectively, we cultured specimens from 19 gastroscopes, 24 colonoscopes and 5 side viewing duodenoscopes during the period of 2011 to 2015. A total of 164 results had complete data denoting date of cleansing, number of days stored and culture results. All scopes underwent initial cleaning in the endoscopy suite utilizing tap water, and then manually cleaned and flushed. High level disinfection was achieved with a Medivator© DSD (Medivator Inc., United States) automated endoscope reprocessor following manufacturer instructions, with Glutacide® (Pharmax Limited, Canada), a 2% glutaraldehyde solution. After disinfection, all scopes were stored in dust free, unfiltered commercial cabinets for up to 7 d. Prior to use, all scopes were sampled and plated on sheep blood agar for 48 h; the colony count was obtained from each plate. The length of endoscope hang time and bacterial load was analyzed utilizing unpaired t-tests. The overall percentage of positive and negative cultures for each type of endoscope was also calculated.RESULTSAll culture results were within the acceptable range (less than 200 cfu/mL). One colonoscope cultured 80 cfu/mL after hanging for 1 d, which was the highest count. ERCP scopes cultured at most 10 cfu, this occurred after 2 and 7 d, and gastroscopes cultured 50 cfu/mL at most, at 1 d. Most cultures were negative for growth, irrespective of the length of hang time. Furthermore, all scopes, with the exception of one colonoscope which had two positive cultures (each of 10 cfu/mL), had at most one positive culture. There was no significant difference in the number of bacteria cultured after 1 d compared to 7 d when all scopes were combined (day 2: P = 0.515; day 3: P = identical; day 4: P = 0.071; day 5: P = 0.470; day 6: P = 0.584; day 7: P = 0.575). There was also no significant difference in the number of bacteria cultured after 1 day compared to 7 d for gastroscopes (day 2: P = 0.895; day 3: P = identical; day 4: P = identical; day 5: P = 0.893; day 6: P = identical; day 7: P = 0.756), colonoscopes (day 2: P = 0.489; day 4: P = 0.493; day 5: P = 0.324; day 6: P = 0.526; day 7: P = identical), or ERCP scopes (day 2: P = identical; day 7: P = 0.685).CONCLUSIONThere is no correlation between hang time and bacterial load. Endoscopes do not need to be reprocessed if reused within a period of 7 d.

Simulated-Use Polytetrafluorethylene Biofilm Model: Repeated Rounds of Complete Reprocessing Lead to Accumulation of Organic Debris and Viable Bacteria.

OBJECTIVE Biofilm has been implicated in bacterial persistence and survival after endoscope reprocessing. In this study, we assessed the impact of different methods of reprocessing on organic residues and viable bacteria after repeated rounds of biofilm formation when each was followed by full reprocessing. METHODS ATS-2015, an artificial test soil containing 5-8 Log10 colony-forming units (CFU) of Enterococcus faecalis and Pseudomonas aeruginosa, was used to form biofilm in polytetrafluroethylene channels overnight on 5 successive days. Each successive day, full pump-assisted cleaning using bristle brushes or pull-through devices in combination with enzymatic or nonenzymatic detergents followed by fully automated endoscope reprocessor disinfection using peracetic acid was performed. Residuals were visualized by scanning electron microscopy (SEM). Destructive testing was used to assess expected cutoffs for adenosine triphosphate (ATP; <200 relative light units), protein (<2 µg/cm2), and viable bacteria count (0 CFU). RESULTS Protein residuals were above 2 µg/cm2, but ATP residuals were <200 relative light units for all methods tested. Only when enzymatic cleaner was used for cleaning were there no viable bacteria detected after disinfection irrespective of whether bristle brushes or pull-through devices were used. SEM revealed that some residual debris remained after all reprocessing methods, but more residuals were detected when a nonenzymatic detergent was used. CONCLUSIONS Surviving E. faecalis and P. aeruginosa were only detected when the non-enzymatic detergent was used, emphasizing the importance of the detergent used for endoscope channel reprocessing. Preventing biofilm formation is critical because not all current reprocessing methods can reliably eliminate viable bacteria within the biofilm matrix. Infect Control Hosp Epidemiol 2017;38:1284-1290.

Improper positioning of the elevator lever of duodenoscopes may lead to sequestered bacteria that survive disinfection by automated endoscope reprocessors

Some outbreaks associated with contaminated duodenoscopes have been attributed to biofilm formation. The objective of this study was to determine whether bacteria within an organic matrix could survive if the elevator lever was improperly positioned in the automated endoscope reprocessor (AER) after 1 round of reprocessing. Duodenoscope lever cavities with an open or sealed elevator wire channel were inoculated with 6-7 Log10 of both Escherichia coli and Enterococcus faecalis in ATS2015 (Healthmark Industries, Fraser, MI) and dried for 2 hours. The duodenoscopes with the lever in the horizontal position were processed through 2 makes of AERs. The cavity was sampled using a flush-brush-flush method to determine the quantity of surviving bacteria. E faecalis (range, 21-6 Log10 CFU) and E coli (range, 0-3 Log10 CFU) survived disinfection of sealed or unsealed elevator wire channel duodenoscopes in 2 different AERs with and without cleaning cycles. If bacteria in organic residue are under the improperly positioned lever, then just 1 round of use is sufficient for bacteria to survive both liquid chemical sterilization and liquid chemical HLD regardless of whether or not the AER had a cleaning cycle.

Evaluation of a new packaging process for non-autoclavable endoscopes: results for the first 100 microbiological samples

A new process for packaging endoscopes (SureStore®, Medical Innovations Group) immediately after they exit from washing and disinfection in an automated endoscope reprocessor (AER) allows for endoscopes to be stored for up to 15 days. To describe the microbiological quality of samples from gastrointestinal endoscopes following this process. Three-month prospective study using microbiological sampling from a stock of 38 gastrointestinal endoscopes carried out in a French University Hospital. The compliance rate (proportion of samples ≤25cfu with no pathogenic micro-organisms) and the rate of sterile samples (proportion of germ-free samples) were calculated. We then used multivariate analysis to determine the factors associated with the maintenance of sterility. One hundred samples were taken from stored endoscopes: 31 stored for ≤3 days, 34 stored between 3 and 7 days, and 35 after storage between 7 and 15 days. The compliance rate was 98% and the sterile sample rate was 60%. Only the time between leaving the AER and packaging was significantly associated with the sterility of samples (P=0.02). The probability of having a sterile sample decreased 17-fold when the endoscope was packaged >2h after leaving the AER (P=0.04) compared to an endoscope packaged within 1h after leaving the AER. The SureStore process seems capable of satisfactorily maintaining compliance (98%) of samples taken from endoscopes stored for up to 15 days. The delay in packaging should not exceed 1h, as the rate of sterile samples decreases thereafter.

Monitoring of endoscope reprocessing with an adenosine triphosphate (ATP) bioluminescence method.

Background: The arising challenges over endoscope reprocessing quality proposes to look for possibilities to measure and control the process of endoscope reprocessing.Aim: The goal of this study was to evaluate the feasibility of monitoring endoscope reprocessing with an adenosine triphosphate (ATP) based bioluminescence system.Methods: 60 samples of eight gastroscopes have been assessed from routine clinical use in a major university hospital in Germany. Endoscopes have been assessed with an ATP system and microbial cultures at different timepoints during the reprocessing. Findings: After the bedside flush the mean ATP level in relative light units (RLU) was 19,437 RLU, after the manual cleaning 667 RLU and after the automated endoscope reprocessor (AER) 227 RLU. After the manual cleaning the mean total viable count (TVC) per endoscope was 15.3 CFU/10 ml, and after the AER 5.7 CFU/10 ml. Our results show that there are reprocessing cycles which are not able to clean a patient used endoscope.Conclusion: Our data suggest that monitoring of flexible endoscope with ATP can identify a number of different influence factors, like the endoscope condition and the endoscopic procedure, or especially the quality of the bedside flush and manual cleaning before the AER. More process control is one option to identify and improve influence factors to finally increase the overall reprocessing quality, best of all by different methods. ATP measurement seems to be a valid technique that allows an immediate repeat of the manual cleaning if the ATP results after manual cleaning exceed the established cutoff of 200 RLU.

Automated endoscope reprocessors.

Automated endoscope reprocessors.

System 83 Plus Automated Endoscope Reprocessors

Biomedical Safety & Standards 46(18):p 137-139, October 15, 2016. | DOI: 10.1097/01.BMSAS.0000503245.53404.e8

ISQUA16-1337MANUAL CLEANING OF ENDOSCOPIC RETROGRADE CHOLANGIOPANCREATOGRAPHY ENDOSCOPES USING REMOTE VIDEO AUDITING

The Society of Gastroenterology Nurses and Associates (SGNA) outlines practice standards for manual cleaning of endoscopic retrograde cholangiopancreatography endoscopes before being placed into an automated endoscope reprocessors (AER) between patients to prevent the transmission of pathogens [1]. Even though there are detailed guidelines for reprocessing endoscopes there have been multiple reports of patients acquiring Carbapenem-Resistant Enterobacteriaceae (CRE) following an endoscopic retrograde cholangiopancreatography (ERCP) [2]. Since pathogen transmission can be related to improper cleaning of the endoscope …

A Pseudo-Outbreak of Pseudomonas putida and Stenotrophomonas maltophilia in a Bronchoscopy Unit

Background: Endoscopes represent the medical devices most commonly linked to health care-associated outbreaks and pseudo-outbreaks. Most of the recent outbreaks and pseudo-outbreaks have resulted from contaminated automated endoscope reprocessors (AER) or the use of damaged or malfunctioning bronchoscopes or contaminated equipment. Objectives: We investigated a pseudo-outbreak of Pseudomonas putida and Stenotrophomonas maltophilia recovered from bronchial washing (BW) specimens obtained during bronchoscopy in a bronchoscopy unit. Methods: Samples were obtained from environmental surfaces in the endoscopy suite, bronchoscopes, and bronchoscopic dispensable material, and specimens of cleaning solutions, cleaning brushes, the AER, and the ultrasound system were sent for bacterial culture. Medical records were reviewed to identify possible infections after a bronchoscopy. Results:P. putida and S. maltophilia were isolated from BW samples of 39 patients. The bronchoscopy models Olympus BF-1T160 and BF-160 were contaminated. Both bronchoscopes and other contaminated material (cleaning brushes, diluted cleaning solutions, and the sink) were isolated, but new cases continued to appear. The AER was recently installed, and new connections were used for the water lines and new tubes were connected to the AER. Initially, specimens were obtained from the external circuits and the internal walls of the AER. Finally, cultures were made from the filters on the water lines, and growth of P. putida and S. maltophilia was found. The investigation revealed that the BW specimens were contaminated because sterile saline was injected by means of the biopsy port of the bronchoscope and was recovered through the same channel by means of the proximal suction port. No patients developed clinical signs or symptoms of infection, but the positive cultures did lead to treatment of 21 patients. Conclusions: We described a pseudo-outbreak related to a contaminated bronchoscope because of inadequate installation of the AER for used new water lines and because the new tubes were connected to the AER. The antibacterial filters of the AER used tap water, and this may have contained low levels of microorganisms. No serious clinical complications derived from this pseudo-outbreak.

Measures to improve microbial quality surveillance of gastrointestinal endoscopes.

Infectious outbreaks associated with the use of gastrointestinal endoscopes have increased in line with the spread of highly resistant bacteria. The aim of this study was to determine the measures required to improve microbial quality surveillance of gastrointestinal endoscopes. We reviewed the results of all microbiological surveillance testing of gastrointestinal endoscopes and automatic endoscope reprocessors (AERs) performed at Brest Teaching Hospital from 1 January 2008 to 1 June 2015. We analyzed the influence of the time of incubation on the rate of positive results using the Kaplan - Meier method. We also studied risk factors for gastrointestinal endoscope contamination using a multivariable logistic regression model. Over the study period, 1100 microbiological tests of gastrointestinal endoscopes (n = 762) and AERs (n = 338) were performed. A total of 264 endoscope tests (34.6 %) showed a level of contamination higher than the target. After 2 days of incubation, contamination was apparent in only 55.5 % of the endoscopes that were later shown to be contaminated (95 % confidence interval [CI] 49.2 - 61.8). Multivariable analysis showed that the use of storage cabinets for heat-sensitive endoscopes significantly reduced the risk of endoscope contamination (odds ratio [OR] 0.23, 95 %CI 0.09 - 0.54; P < 0.001) and that the use of endoscopes older than 4 years significantly increased this risk (OR ≥ 6 vs. < 2 years 2.92, 95 %CI 1.63 - 5.24; P < 0.001). Microbiological culture technique, mainly incubation duration, strongly influenced the results of endoscope sampling. Samples should be cultured for more than 2 days to improve the detection of contaminated endoscopes. Particular attention should be paid to endoscopes older than 2 years and to those that are not stored in storage cabinets for heat-sensitive endoscopes.